相关论文: Capture of field stars by dark substructures
When a dark matter halo falls into a more massive object and becomes a subhalo, it typically loses much of its mass through tidal stripping. The reverse process is also possible in principle. The subhalo may gravitationally capture material…
Dark matter (DM) subhalos offer critical tests of cosmological models through their abundance and properties, yet most remain undetectable due to their lack of stars. We investigate whether their presence leaves measurable imprints on the…
We studied the rate at which stars capture dark matter (DM) particles, considering different assumptions regarding the DM characteristics and in particular investigating how the stellar physics influences the capture rate. Two scenarios…
We use analytical and N-body methods to examine the survival of wide stellar binaries against repeated encounters with dark substructures orbiting in the dark matter haloes of dwarf spheroidal galaxies (dSphs). Our models adopt…
If captured by the gravitational field of stars or other compact objects, dark matter can self-annihilate and produce a potentially detectable particle flux. In the case of superheavy dark matter ($ m_{X} \gtrsim 10^{8} GeV $), a large…
Among the most explored directions in the study of dense stellar systems is the investigation of the effects of the retention of supernova remnants, especially that of the massive stellar remnant black holes (BHs), in star clusters. By…
This paper shows that gravitating bodies travelling through the Galaxy can trap lighter interstellar particles that pass nearby with small relative velocities onto temporarily-bound orbits. The capture mechanism is driven by the Galactic…
In the solar neighbourhood, there are moving groups of stars with similar ages and others of stars with heterogeneous ages as the field stars. To explain these facts, we have constructed a simple model of three phases. Phase A: a giant…
We propose a dynamical mechanism for capturing stars around a massive black hole (MBH), which is based on the accumulation there of a very dense cluster of compact stellar remnants. This study is motivated by the presence of ~10 young…
We use controlled $N$-body experiments to study the dynamical evolution of dwarf spheroidal galaxies (dSphs) embedded in dark-matter (DM) haloes containing a large population of dark subhaloes. We show that stellar orbits subject to…
Dark Matter (DM) can be trapped by the gravitational field of any star, since collisions with nuclei in dense environments can slow down the DM particle below the escape velocity ($v_{esc}$) at the surface of the star. If captured, the DM…
Compact stellar objects are promising cosmic laboratories to test the nature of dark matter (DM). DM captured by the strong gravitational field of these stellar remnants transfers kinetic energy to the star during the collision. This can…
We use N-body simulations to study the tidal evolution of globular clusters (GCs) in dwarf spheroidal (dSph) galaxies. Our models adopt a cosmologically motivated scenario in which the dSph is approximated by a static NFW halo with a…
We use analytical and $N$-body methods to study the evolution of dwarf spheroidal galaxies (dSphs) embedded in dark matter (DM) haloes that host a sizeable subhalo population. Dark subhaloes generate a fluctuating gravitational field that…
The high multiplicity of massive stars in dense, young clusters is established early in their evolution. The mechanism behind this remains unresolved. Recent results suggest that massive protostars may capture companions through disk…
The local group dwarf spheroidal galaxies (LG dSphs) are among the most promising astrophysical targets for probing the small scale structure of dark matter (DM) subhalos. We describe a method for testing the correspondence between proposed…
A significant fraction of the stellar population in the cusp around central black holes of galaxies consists of compact remnants of evolved stars, such as white dwarfs, neutron stars and stellar mass black holes. We estimate the rate of…
We review numerical work carried out over the last decade on the role of environmental mechanisms in shaping the nature of the faintest galaxies known, dwarf spheroidals (dSphs). In particular we discuss a model in which dSphs originated…
A review is presented on the properties, origin and evolutionary links of hot subluminous stars which are generally believed to be extreme Horizontal Branch stars or closely related objects. Amongst the field stars a large fraction of sdBs…
We identified globular clusters and field stars of extragalactic origin and investigated their chemical, physical, and kinematical properties. This objects as supposed was captured by the Galaxy at different times from debris of the dwarf…